Mechanical pencil



Get. 15; 1935. c. E. WEHN MECHANICAL PENCIL Filed Oct. 30, 1954INVENTOR.

6442111 are/1w.

Maw I ATTORNE s.

Patented Oct. 15, 1935 UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to mechanical pencils and especially to apropelled type of pencil employing a spring tension tip which grips thelead adjacent the point of use.

The object of the present invention is to generally improve and simplifythe construction and operation of pencils of the character described; toreduce to a minimum the number of parts required; to provide a pencilcomprising a main barrel section, a point or lead-carrying section, andan actuating section, said actuating section being interposed betweenthe barrel and point sections and being rotatable with relation to thebarrel section but non-rotatable with relation to the point section, andsaid point section being carried by the actuating section and beingremovable with relation thereto when a new lead is to be inserted; toprovide a threaded push rod for advancement of the lead which isnon-rotatable with relation to the lead; to provide a member carried bythe barrel section for supporting and anchoring the actuating sectionwith relation to the barrel section, said anchoring member leaving theactuating section free for rotation;

and, further, to provide a driving member formed in or carried by theactuating section for rotating the threaded push rod with relation to anut carried by the anchor member.

The invention is shown by way of illustration in the accompanyingdrawing, in which- Fig. 1 is a central vertical longitudinal section ofthe pencil;

Fig. 2 is a longitudinal section of the anchor member;

Fig. 3 is a cross section on line IIIIII of Fig. 1;

Fig. 4 is a cross section on line IV-IV of Fig. 1;

Fig. 5 is a perspective view of the pusher rod; and

Fig. 6 is a perspective view of the driving member.

Referring to the drawing in detail, and particularly to Fig. 1, Aindicates the main or barrel section of the pencil; B, the point oflead-carrying section; and C, the actuating section. The severalsections are disposed end to end and are secured with relation to eachother, as will hereinafter be described.

Formed in one end of the barrel section is a central passage 2, andsecured therein is a tubular member 3 which will hereinafter be referredto as the anchor member. The anchor member is secured in the passage inany suitable manner,

I and one end of the anchor member projects heyond the barrel sectioninto'the actuating section C, the projecting end of the anchor memberbeing provided with an annular shoulder 4 and an internal threadedpassage 5 which will function as a nut. The shoulder 4 which is formed 5on the outer end of the anchor member secures the actuating section Cagainst endwise removal with relation to the barrel but it permits freerotation of the actuating section.

Mounted within the tubular anchor member is 10 a push bar, generallyindicated at 6. This bar is flat and its opposite edges are threaded, asindicated at l. One end of the bar is flattened, as shown at 8, to formshoulders which engage the nut 5, and as such limits outward movement of15 the pusher rod. The rodis threaded to engage with the nut 5 and meansmust be provided for rotating the pusher rod so that it may be advancedor retracted with relation to the point section B, as the case may be.This is accomplished as follows:

Suitably secured in the actuating section is a driving member whichconsists of a sleeve 9, one end of which is open while the other end ispartially closed, as indicated at 10. A rectangular shaped slot H isformed in the partially closed end of the driving member and the pusherrod extends therethrough. The pusher rod is freely movable in anendwisedirection in relation to the driving member, but the sides of therectangular shaped slot ll engage the fiat side of the pusher rod;hence, if the actuating member C and the driving member secured thereinare rotated, rotary motion will be transmitted to the pusher bar and asit rotates with relation to the stationary nut 5, the rod will either beadvanced or retracted with relation to the point sections,depending'upon the direction, of rotation of the member C.

The point or lead-carrying section B, as pre- 40 viously stated, iscarried by the actuating section C; that is, the forward end of theactuating section is internally threaded, as shown at l2, to receive thethreaded end l3 of the point section. The point section isotherwise'provided with a central passage for the reception of a leadl4; and it is also provided with a spring tension tip l5 whereby thelead is gripped adjacent the point of use.

The assembly of the mechanism is accomplished as follows: The pusher rodis first inserted through the inner end 3a of the tube and screwedthrough the nut 5 until it projects slightly beyond the same. The innerend 3a of the tube is then spun over, as indicated at 3b (see Fig. 1),and when this is accomplished the pusher rod will be permanently securedagainst removal as the shouldered end 8 of the pusher rod will engagethe spun-over section of the inner end of the tube when the pusher rodreaches its innermost position; similarly the shouldered end 8 willengage the inner end of the nut 5 when it reaches its outermostposition. After the pusher rod has been secured in position in the tubeor anchor member 3, it is pushed through the actuating member C untilthe shoulder t engages an inner shoulder 4a on the actuating member. Theanchor member is then inserted in the central passage 2 of the barrelsection and pushed inwardly until a snug fit is formed between theadjacent end faces of the barrel section and the actuating section, itbeing understood that the tubular member or anchor member 3 is pressedor otherwise forced into the barrel section so that it will be rigidlysecured when it finally reaches position.

After these parts have been assembled, the driving'member 9 is insertedin the actuating section. This is also pressed in and as the outersurface is knurled or roughened, as indicated at 9a, it will be rigidlysecured. It is then only necessary to apply the point section byscrewing it into the threaded open end of the actuating section, andthat completes the assembly.

The operation will be as follows: After a lead such as shown at M, hasbeen placed in the point or lead-carrying section and it is desired toadvance the lead,'it is only necessary to grasp the barrel with one handand the actuating section with the other and to rotate the two membersrelative to each other. Assuming that the actuating section is rotatedand the barrel held still, the driving member will transmit a rotarymovement to the pusher bar and as the nut 5 is sta tionary, the pusherbar will advance providing the actuating member is rotated in the rightdirection, and as the pusher rod engages the inner end of the lead l4,it will be pushed outwardly through the spring tension tip I5. If thelead has been too far advanced and it is desired to return it, it isonly necessary to rotate the actuating member in the opposite directionas this will cause retraction of the pusher rod; and when the pusher rodhas been retracted a suitable distance, it is only necessary to apply aninward pressure'to' the outer end of the lead to force it back thedistance desired.

The mechanism here shown is exceedingly simple in construction, thenumber of parts required is reduced to a minimum, and the problem ofassembling is easily and quickly accomplished. The pencil is dividedinto three sections but two of them are non-rotatable 'with relation toeach other, to-wit, the actuating section and the point or lead-carryingsection; hence it is only the barrel proper or the actuating sectionwhich may be rotated, thus simplifying the operation of advancing thelead as it wears away.

The entire mechanism is concealed within the pencil and is at no timeexposed, thereby preventing tampering with the mechanism.

The pusher bar and the lead are non-rotatable with relation to eachother, which is a very desirable feature as cutting away of the innerend of the lead is prevented and the dust that would be formed will notclog or foul the operating parts of the mechanism; also, the pencil iscleaner.

The lead-carrying chamber may be formed in the head ofthe barrel, asshown at l8, and a cap may be applied as shown at I9; also, an

1 eraser may be applied if desired; but these features are common tomost pencils of this character and form no part of the presentconstruction.

The only parts subject to wear are the threaded pusher bar and nut, butthis wear is reduced to 5' a minimum in the present instance becausedouble, triple, or quadruple threads may be employed. There may also bea slight amount of wear at the point where the actuating member rotatesabout the outer end of the anchor mem- 10 her; and also a slight amountof wear between the contacting faces 20; but this wear can readily betaken up by removing the point or lead-carrying section and tapping orapplying endwise pressure to the driving member so as to cause 15 theanchor member to be driven into the barrel section. Hence, wear iseasily compensated for and a long life and dependable operation areinsured.

While I have shown the preferred form of my 20 invention; it is to beunderstood'that various changes may be made in its construction by thoseskilled in the art without departing from the spirit of the invention asdefined in the appended claims. 2:1

Having described my invention, what I claim and desire to secure byLetters Patent is-- 1. In a pencil of the character described, a barrelsection, alead-carrying section and an actuating section disposedbetween the lead-carrying 30 and the lead-carrying section, a pusher rodcar- 40 1 ried by the anchor member, and means actuated by relativerotationof the actuating section and the barrel section for impartinglongitudinal movement to the pusher rod and the lead in thelead-carrying section. 45

2. In a pencil of the character. described, a barrel section, alead-carrying section, and an actuating section disposed between thelead-carrying section and the barrel section, ananchor member secured inthe barrel section and extend-' 50 ing into the actuating section, saidanchor member having a shoulder engaging a shoulder in theactuatingsection and securing-the actuating section against endwise removal from'the barrel section but permitting free rotation of 55 the actuatingsection about the anchor member,

a detachable connection between the actuating section and thelead-carrying section, a threaded pusher rod' carried by the anchormember, means actuated by rotation of the actuating section for 50rotating the pusher rod, and a nut in the anchor member through whichthe pusher rod extends and whereby longitudinal movement of the pusherrod is produced by the rotation thereof.

3; In a pencil of the character described, a bar- 5 rel section, alead-carrying section, and an actuating section disposedbetween thelead-carrying section and the barrel section, an anchor member securedin the barrel section and extending into the actuating section, saidanchor member having a shoulder engaging a shoulder in the actuatingsection and securing the actuating section against endwise removal fromthe barrel section'but permitting free rotation of the actuating sectionabout the anchor member, a detachable connection between the actuatingsection and the lead-carrying section, a threaded pusher rod carried bythe anchor member, a driving member secured in the actuating section tocause the pusher rod to rotate with the actuating member, and a nut inthe anchor member through which the pusher rod extends and wherebylongitudinal movement of the pusher rod is produced by rotation thereof.

4. In a pencil of the character described, a barrel section, alead-carrying section, and an actuating section disposed between thelead-carrying section and the barrel section, an anchor member securedin the barrel section and extending into the actuating section, saidanchor member having a shoulder engaging a shoulder in the actuatingsection and securing the actuating section against endwise removal fromthe barrel section but permitting free rotation of the actuating sectionabout the anchor member, a detachable connection between the actuatingsection and the lead-carrying section, a threaded pusher rod carried bythe anchor member, a driving member in the actuating section to causethe pusher rod to rotate with the actuating member, a nut in the anchormember through which the pusher rod extends and whereby longitudinalmovement of the pusher rod is produced by rotation thereof, and meansfor limiting longitudinal movement of the pusher rod in eitherdirection.

5. In a pencil of the character described, a barrel section, a tubularanchor member secured against rotation and endwise movement in saidbarrel section and projecting beyond one end of the barrel section, anactuating section rotatably mounted on the projecting end of the anchormember, a shoulder on the anchor member engaging a shoulder in theactuating member to secure the actuating section against endwiseremoval, a nut in the anchor member, a threaded pusher rod disposedwithin the tubular anchor member and having threaded engagement with thenut, and means forming a driving connection between the actuating memberand the pusher rod whereby relative rotation between the pusher rod andnut is obtained.

6. In a pencil of the character described, a

barrel section, a tubular anchor member secured against rotation andendwise movement in said barrel section and projecting beyond one end ofthe barrel section, an actuating section rotatably mounted on theprojecting end of the 5 anchor member, a shoulder on the anchor memberengaging a shoulder in the actuating memher to secure the actuatingsection against endwise removal, a nut in the anchor member, a threadedpusher rod disposed within the tubular anchor member and having threadedengagement with the nut, means for forming a driving connection betweenthe actuating member and the pusher rod whereby relative rotationbetween the pusher rod and nut is obtained, and a point sectiondetachably secured to the actuating section and having a passage formedtherein in alignment with the pusher rod, said passage being formed forthe reception of a lead, said point and the lead carried therebybeingnonrotatable with relation to the pusher rod and the actuating section.

7. In a pencil of the character described, a barrel section, a tubularanchor member secured against rotation and endwise movement in saidbarrel section and projecting beyond one end of the barrel section, anactuating section rotatably mounted on the projecting end of the anchormember, a shoulder on the anchor member engaging a shoulder in theactuating member to secure the actuating section against endwiseremoval, a nut in the anchor member, a threaded pusher rod disposedwithin the tubular anchor member and having threaded engagement with thenut, means for forming a driving connection between the actuating memberand. the pusher rod whereby relative rotation between the pusher rod andnut is obtained, a point section detachably secured to the actuatingsection and having a passage formed therein in alignment with the pusherrod, said passage being formed for the reception of a lead, said pointand the lead carried thereby being non-rotatable with relation to thepusher rod and the actuating section, and means for limitinglongitudinal movement of the pusher rod with relation to the nut.

CHARLES E. WEHN.

